PB1732: CLINICAL CHARACTERISTICS AND THERAPEUTIC RESULTS OF CHILDHOOD AND YOUNG ADULTS T - ACUTE LYMPHOBLASTIC LEUKEMIA IN SOUTH OF TUNISIA
Authors: Imen Frikha, Aicha Ben Kahla, Moez Medhaffer, Nour Louati, Imen Ben Amor, Latifa Khalifa, Olfa Kassar, Yossra Fakhfakh, Faten Kallel, Maha Charfi, Sondes Hdijji, Moez Elloumi, Ikram Ben Amor
Journal: HemaSphere (2023)

Topic: 2. Acute lymphoblastic leukemia - Clinical Background: T-cell acute lymphoblastic leukemia (T-ALL) accounts for approximately 12–15% of newly diagnosed ALL cases. Due to intensive therapy, outcomes in T-ALL are steadily improving with 5-year event-free survival (EFS) reaching more than 80%. Acute lymphoblastic leukemia is thought to have distinctive features in Tunisian children and young adults. The analysis of T-ALL allowed a better study of their characteristics as well as their evolution after treatment. Aims: The aim of this study was to determine the clinical and biological characteristics of T-ALL and to the analysis of T-ALL to allow a better study of their characteristics as well as their evolution after treatment. Methods: In this study, we enrolled retrospectively all cases of patients under 30 years old, with T-ALL diagnosed in the hematology department of Hedi Chaker Hospital of Sfax, Tunisia, between January 2000 and December 2021. All patients were treated with the EORTC 58951 pediatric protocol. We studied the epidemiological characteristics (age, sex, clinical and biological signs). We also studied the therapeutic outcomes: complete remission, overall survival (OS), event-free survival (EFS), and relapse rate. Results: We enrolled 130 cases of T-ALL (33%) of all ALL diagnosed during this period. Forty-six cases (36%) of these T-ALL were aged more than 15 years. The sex ratio M/F was 2.1. A tumor syndrome was noted in 113 cases (88%), of which 37 cases were young adults (29%). Hyperleukocytosis of more than 100 G/L was detected in 47 cases (36%). Cytogenetic abnormalities were found in 42 patients (31%). On the 7th day of treatment with corticosteroids, 38% of cases were corticoresistant. According to risk group stratification, 73 cases (56%) were classified into medium risk 2 (MR2) and 57 cases (45%) into high risk (HR). The rate of complete remission (CR) was 86% (112 cases). The rate of toxic death was 27%. Allogeneic bone marrow transplantation was performed in 15 of 25 patients with CR of the HR group. Relapse occurred in 30 patients (27%). With a median follow-up of 159 months (13 years), OS and EFS at 5 years were respectively 54 and 53%. Summary/Conclusion: The frequency of T-ALL in our series (32%) is higher than those described in the literature (10 to 15%). This high frequency is also found in other Tunisian series as well as in the Tunisian multicenter study of 2005 (37%). The frequency of corticoresistance in our study (38%) is comparable to the literature (38 to 40%). The CR rate in our series was 86%, comparable to the literature (80 to 90%). However, the overall survival at 5 years was 54% lower than in the literature (70-80%), which could be explained by the high rate of toxic death (27%). Our therapeutic results could be improved by using other therapeutic arms particularly immuno-therapy such Nelarabine and CART-cells. Keywords: Young adult, Acute lymphoblastic leukemia, Children